CN114222506A - Hookah device with dielectric heater - Google Patents

Abstract

A hookah apparatus (50) for heating an aerosol-forming substrate (92) to generate an aerosol, an aerosol-generating article (90) for a hookah system and a hookah system comprising a hookah apparatus (50) and an aerosol-generating article (90), the hookah apparatus (50) comprising: a liquid chamber (54) configured to contain a volume of liquid, the liquid chamber (54) having a headspace outlet (60); an article cavity (14) configured to receive an aerosol-forming substrate (92), the article cavity (14) being in fluid communication with the liquid cavity (54); and an electromagnetic field generator (11) configured to generate a Radio Frequency (RF) electromagnetic field in the article cavity (14).

Description

Hookah device with dielectric heater

Technical Field

The present disclosure relates to a hookah system for generating an aerosol from an aerosol-forming substrate. In particular, the present disclosure relates to hookah systems, hookah devices, and hookah articles for use with hookah devices.

Background

Conventional hookah apparatus are sometimes referred to in the art as hookah, or hookah pipe. Conventional hookah devices differ from other aerosol generating devices in that volatile compounds released from a heated substrate in the hookah device are drawn through a liquid pool prior to inhalation by a user. Conventional hookah apparatus may include one outlet or more than one outlet so that the apparatus may be used by more than one user at a time.

Typically, conventional hookah apparatus are used in combination with a hookah substrate, sometimes referred to in the art as hookah tobacco, tobacco molasses, or simply molasses. The sugar of conventional hookah substrates is relatively high, in some cases including up to about 50% sugar, while about 20% sugar can be found in conventional combustible cigarettes.

Conventional hookah devices also use charcoal to heat, and sometimes burn, the hookah substrate to generate an aerosol for inhalation by the user. Heating the hookah substrate with charcoal may result in complete or partial combustion of the tobacco or other components in the hookah substrate.

Different types of electrically operated hookah systems are proposed. The electrically operated hookah system replaces the charcoal heat source of a conventional hookah apparatus with an electric heater. Almost all proposed electrically operated hookah systems heat the aerosol-forming substrate by one or more of: conducting heat from the heating element to the aerosol-forming substrate, radiating heat from the heating element to the aerosol-forming substrate, or drawing heated air through the aerosol-forming substrate. This is most commonly achieved by passing an electric current through a resistive heating element, causing joule heating of the heating element. Induction heating systems have also been proposed in which joule heating is due to eddy currents induced in the susceptor heating element.

One problem with the electrically operated hookah devices previously proposed is that they may cause uneven heating of the aerosol-forming substrate. The portion of the aerosol-forming substrate closest to the heating element heats up faster or to a higher temperature than the portion of the aerosol-forming substrate further away from the heating element.

It is desirable to be able to provide uniform heating of an aerosol-forming substrate in a manner that allows for greater design flexibility and allows for control of heating.

Disclosure of Invention

In the present disclosure, there is provided a hookah apparatus for heating an aerosol-forming substrate to generate an aerosol. The hookah apparatus may include a liquid chamber configured to hold a volume of liquid. The liquid chamber may have a headspace outlet. The hookah apparatus may comprise an article cavity configured to receive an aerosol-forming substrate. The product chamber may be in fluid communication with the liquid chamber. The hookah apparatus may comprise: an electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article lumen.

In particular, in the present disclosure there is provided a hookah apparatus for heating an aerosol-forming substrate to produce an aerosol, the hookah apparatus comprising: a liquid chamber configured to contain a volume of liquid, the liquid chamber having a headspace outlet; an article cavity configured to receive an aerosol-forming substrate, the article cavity being in fluid communication with the liquid cavity; and an electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article cavity.

Such a hookah apparatus is configured to generate dielectric heating of an aerosol-forming substrate. The dielectric heating may be uniform within a volume of aerosol-forming substrate without creating hot spots. Dielectric heating also does not require contact between the heating element and the aerosol-forming substrate. This means that there is no need to clean the heating element, as compared to conventional arrangements, where the electrical heating element may accumulate aerosol residues thereon. The hookah apparatus allows considerable design flexibility in the shape, volume and composition of the aerosol-forming substrate and the shape and volume of the corresponding article cavity.

The electromagnetic field generator may be any suitable type of electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article lumen.

Preferably, the electromagnetic field generator comprises a solid state RF transistor.

The use of solid state RF transistors makes the hookah apparatus compact. Conventional devices for generating RF frequency radiation for heating, such as in a domestic microwave oven, are magnetrons. Magnetrons are bulky and require high voltages to operate. In addition, the magnetron has a relatively unstable frequency output and has a relatively short lifetime. RF transistors can provide consistent operation over more cycles of use and require much lower operating voltages.

Advantageously, the solid state RF transistor is configured to generate and amplify an RF electromagnetic field. The use of a single transistor to provide generation and amplification of the RF electromagnetic field allows the hookah apparatus to be compact. The solid state RF transistor may be, for example, an LDMOS transistor, a GaAs FET, a SiC MESFET, or a GaN HFET.

Although it is preferred that the electromagnetic field generator comprises a solid state RF transistor, it is envisaged that in some embodiments the electromagnetic field generator may comprise a magnetron or other suitable electromagnetic field generator capable of generating an RF electromagnetic field.

As used herein, Radio Frequency (RF) means a frequency between about 3 hertz (Hz) and about 3 terahertz (THz). Thus, as used herein, RF frequencies include microwave frequencies. Preferably, the RF electromagnetic field has a frequency between about 1 megahertz (MHz) and about 50 gigahertz (GHz). More preferably, the RF electromagnetic field has a frequency between about 4 megahertz (MHz) and about 30 gigahertz (GHz). The RF electromagnetic field may have a frequency between about 100 megahertz (MHz) and about 10 gigahertz (GHz). In one embodiment, the RF electromagnetic field has a frequency of about 4 megahertz (GHz). In one embodiment, the RF electromagnetic field has a frequency of about 3 gigahertz (GHz). In one embodiment, the RF electromagnetic field has a frequency of about 2.4 gigahertz (GHz).

As used herein, the term "aerosol-forming substrate" relates to a substrate capable of releasing volatile compounds, which may form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate is typically part of an aerosol-generating article. For example, the aerosol-forming substrate may be an aqueous aerosol-forming substrate.

The aqueous smoke sol-forming matrix may also be referred to in the art as aqueous tobacco, tobacco molasses, or simply molasses. The sugar of the aqueous aerosol-forming substrate may be relatively high compared to a conventional combustible cigarette or a tobacco-based consumable intended to be heated without combustion to simulate a smoking experience. The aerosol-forming substrate will be described in more detail later.

As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing volatile compounds that can form an aerosol. For example, the aerosol-generating article may be a cartridge for a hookah apparatus. A cartridge for a hookah apparatus comprises an aerosol-forming substrate. Preferably, the cartridge for the hookah apparatus comprises a hookah aerosol-forming substrate. A cartridge for a hookah device is receivable by the hookah device and operates with the hookah device to generate an aerosol that can be inhaled by a user drawing or inhaling on a mouthpiece of the hookah device. The aerosol-generating article may be disposable.

As used herein, the term "hookah device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The hookah apparatus is separate from the aerosol-forming substrate. The hookah device is configured to be combined with an aerosol-forming substrate for heating the aerosol-forming substrate. The aerosol-forming substrate may be provided as part of an aerosol-generating article. The hookah apparatus is separate from the aerosol generating article. The hookah device is configured to be combined with an aerosol-generating article for heating an aerosol-forming substrate of the aerosol-generating article. A hookah device differs from other aerosol generating devices at least in that volatile compounds released from a heated substrate are drawn through a liquid pool of the hookah device prior to inhalation by a user. The hookah apparatus may include more than one outlet so that the apparatus may be used by more than one user at a time. The hookah apparatus may comprise an airflow conduit, such as a rod tube, for directing volatile compounds released from the aerosol-forming substrate to the liquid pool.

As used herein, the term "hookah system" refers to the combination of a hookah device with an aerosol-forming substrate or with an aerosol-generating article comprising an aerosol-forming substrate. In a hookah system, an aerosol-forming substrate or an aerosol-generating article comprising an aerosol-forming substrate and a hookah device cooperate to produce an aerosol.

Hookah devices differ from other aerosol generating devices in that the aerosol produced by the hookah device is drawn through a volume of liquid (typically water) before the user inhales the aerosol. In more detail, when a user draws on the hookah apparatus, volatile compounds released from the heated aerosol-forming substrate are drawn into a volume of liquid through the airflow conduit of the hookah apparatus. The volatile compounds are drawn from the volume of liquid into the headspace of the hookah apparatus, where the volatile compounds form an aerosol. The aerosol in the headspace is then drawn out of the headspace at the headspace outlet for inhalation by the user. A volume of liquid, typically water, is used to reduce the temperature of the volatile compounds and may impart additional water content to the aerosol formed in the headspace of the hookah apparatus. This process adds unique characteristics to the process of using the hookah apparatus by the user and imparts unique characteristics to the aerosol generated by the hookah apparatus and inhaled by the user.

In some preferred embodiments, the hookah device comprises an airflow conduit for conveying volatile compounds released from the heated aerosol-forming substrate from the article cavity to the liquid cavity. More particularly, the hookah apparatus may comprise an air flow conduit configured to transport volatile compounds released from the heated aerosol-forming substrate from the article cavity to a volume of liquid in the liquid cavity. Typically, the gas flow conduit is configured to deliver aerosol from the product chamber below a liquid fill level in the liquid chamber. The liquid filling level in the liquid chamber is the level at which the liquid chamber is intended to be filled with liquid, so that the hookah apparatus can operate optimally. The gas flow conduit may have an opening in the liquid chamber below the liquid filling level of the liquid chamber.

The hookah apparatus includes a headspace outlet. The headspace outlet is the outlet through which the aerosol can be drawn from the liquid chamber. The headspace outlet may be arranged above the liquid filling level of the liquid chamber. The space above the liquid filling level of the liquid chamber is called the headspace. The headspace in the liquid chamber is the space where volatile compounds drawn from the article chamber and through the volume of liquid in the liquid chamber can condense to form an aerosol suitable for inhalation by a user. The headspace in the liquid chamber is not intended to include any volume of liquid in the liquid chamber. Thus, the headspace may be arranged above the liquid filling level of the liquid chamber, which is the level at which the liquid chamber is intended to be filled with liquid. The headspace outlet may be arranged to enable drawing of aerosol from the liquid chamber. The headspace outlet may be in fluid communication with the headspace.

A mouthpiece may be fluidly connected to the headspace outlet. The mouthpiece may be configured for a user to draw on and receive an aerosol generated by a hookah apparatus. In some embodiments, the mouthpiece may be secured to the headspace outlet. In other words, the mouthpiece may be attached to the headspace outlet such that the mouthpiece may not be removed from the headspace outlet without damaging one or both of the mouthpiece and the headspace outlet. The mouthpiece may be removably connected to the headspace outlet. In other words, the mouthpiece may be configured to be attached to and removed from the headspace outlet. In some embodiments, the mouthpiece may be interchangeable with a removable one wait for air valve. In this way, where more than one headspace outlet is provided, the number of mouthpieces may be adjusted according to the number of users in any given session of use without adversely affecting the Resistance To Draw (RTD) of the device. The mouthpiece may comprise a hose connected to the headspace outlet. The hose may be a flexible hose.

The mouthpiece may comprise an activation element. The activation element may comprise a switch that may be activated by a user. The mouthpiece may comprise a puff sensor arranged to detect user puffs on the mouthpiece. The activation element may include both a switch that can be activated by a user and a puff sensor. The activation element may be operably coupled to the control circuit of the hookah apparatus. The activation element may be wirelessly coupled to the control circuit of the hookah apparatus. Activation of the activation element may cause the control circuit of the hookah apparatus to activate the heating element, rather than continuously supplying power to the heating element. Thus, the use of an actuating element may serve to save energy relative to devices that do not employ such elements to provide on-demand heating rather than constant heating.

The hookah apparatus may comprise a plurality of headspace outlets. For example, the hookah apparatus may comprise two, three, four, five or six headspace outlets. Providing more than one headspace outlet may enable more than one user to draw aerosol from the liquid chamber at one time. In other words, providing multiple headspace outlets may enable multiple users to use the hookah apparatus simultaneously.

The hookah device comprises an article cavity configured to receive an aerosol-generating article comprising an aerosol-forming substrate.

It is desirable to contain within the article cavity electromagnetic radiation generated by the electromagnetic field generator. This is to achieve efficient heating and to avoid radiation leakage. Such radiation leakage may cause damage to other components of the system, including the electromagnetic field generator itself. It is also desirable to minimize exposure of the user to RF radiation. Advantageously, the article cavity may comprise one or more external walls formed of a material that is opaque to RF electromagnetic fields. One or more of the exterior walls of the article cavity may comprise any suitable material that is opaque to RF radiation, such as aluminum, stainless steel, silver, or gold. One or more of the exterior walls of the article cavity may have a polished surface to improve reflection of RF radiation within the cavity.

It must also allow radiation to enter the product cavity. Thus, one or more slots may be formed in one or more of the exterior walls to allow the electromagnetic field to enter the article cavity. One or more slots are provided through which the electromagnetic field can pass, allowing the electromagnetic field to enter the article cavity. The one or more slots may have any suitable shape and size to allow the electromagnetic field to enter the article cavity. For example, at least one of the one or more slots may have an L-shape, S-shape, T-shape, or I-shape.

The article cavity may include one or more walls that are transparent to the RF electromagnetic field. In particular, the product cavity may comprise one or more walls that are permeable to RF electromagnetic fields, wherein the aerosol-forming substrate is enclosed in a package or container formed from a material that is impermeable to RF electromagnetic fields. One or more slots may be formed in a wrapper or receptacle enclosing the aerosol-forming substrate to allow entry of the electromagnetic field.

The article cavities can have any suitable shape and size. In particular, the article cavity may have a complementary shape and size to the aerosol-generating article.

The article cavity can have any suitable cross-section. For example, the article cavities may have a circular, oval, rectangular, square, triangular, or any other polygonal cross-sectional shape.

In some embodiments, the article cavity is substantially cylindrical.

In some embodiments, the article cavity is substantially frustoconical. In some embodiments, the width or diameter of one end of the article cavity is greater than the width or diameter of the other end of the article cavity. In other words, the article cavity may taper from one end to the other. Providing the article cavity with one end that is narrower than the other end may enable the article cavity to retain the aerosol-generating article in the article cavity under the influence of gravity only.

The article cavity may include an opening. The article cavity may be configured to receive an aerosol-forming article containing an aerosol-forming substrate through the opening. The article cavity may include an open end. The article cavity may be configured to receive an aerosol-forming article containing an aerosol-forming substrate through the open end.

In some embodiments, the article cavity may include a movable closure. The movable closure may be configured to substantially close the open end of the product cavity. When the movable closure is arranged to substantially close the open end of the article cavity, the movable closure may substantially prevent the aerosol-forming article from being removed from the article cavity. The movable closure may be rotatable to close the open end of the product chamber. The movable closure may be slidable to close the open end of the product cavity. A movable closure may be removably coupled to the open end of the article cavity to substantially close the open end of the article cavity.

In some embodiments, the article cavity may include two open ends. For example, the article cavity may include a first open end and a second open end opposite the first end. Advantageously, providing two open ends to the article cavity may enable air to be drawn through the article cavity between the open ends.

In some embodiments, the article cavity can include an open end and a closed end. The closed end may enable the article cavity to retain the aerosol-generating article in the article cavity.

In some particularly preferred embodiments, the article cavity is substantially frustoconical, having a first end that is narrower than a second end. In these embodiments, the first end of the article cavity may be open and the second end of the article cavity may be open. This may enable air to be drawn through the article cavity from the first end to the second end. In these embodiments, an aerosol-generating article configured to be received in an article cavity may comprise a fluid permeable first end exterior surface and a fluid permeable second end exterior surface. The fluid permeable first and second end exterior surfaces of the aerosol-generating article may enable air to flow through the article cavity between the first and second ends when the aerosol-generating article is received in the article cavity. In these embodiments, it is preferred that the fluid permeable first and second end outer surfaces of the aerosol-generating article are impervious to RF electromagnetic fields. For example, the fluid permeable first and second end exterior surfaces may be formed from a metal mesh.

The article cavities can have any suitable shape and size. The article cavity may have a length between about 10 millimeters and about 100 millimeters, a length between about 20 millimeters and about 90 millimeters, or a length between about 25 millimeters and about 80 millimeters. In some preferred embodiments, the article cavities may have a length of about 33 millimeters, about 34 millimeters, about 35 millimeters, about 36 millimeters, about 37 millimeters, about 38 millimeters, 39 millimeters, about 40 millimeters, about 41 millimeters, or about 42 millimeters. The article cavity may have a width or diameter of between about 5 millimeters and about 70 millimeters, or a width or diameter of between about 10 millimeters and about 60 millimeters, or a width or diameter of between about 10 millimeters and about 50 millimeters. In some preferred embodiments, the article cavities may have a width or diameter of about 35 millimeters, about 36 millimeters, about 37 millimeters, about 38 millimeters, 39 millimeters, about 40 millimeters, about 41 millimeters, about 42 millimeters, about 43 millimeters, about 44 millimeters, or about 45 millimeters.

As used herein, the term "length" refers to the largest longitudinal dimension between the base or bottom end and the top end of a hookah device, a component of a hookah device, an aerosol-generating article, or a component of an aerosol-generating article. As used herein, the term "width" or "diameter" refers to the largest transverse dimension of a hookah device, a component of a hookah device, an aerosol-generating article, or a component of an aerosol-generating article. For example, when the aerosol-generating article has a frusto-conical shape, the width or diameter of the aerosol-generating article is the width or diameter of the frusto-conical shape, which is the widest portion of the aerosol-generating article at any point along the length of the aerosol-generating article. The transverse dimension is a dimension measured in a direction transverse to the longitudinal direction, which is the direction in which the longitudinal dimension is measured. As used herein, the term "cross-section" refers to a section taken along a transverse plane.

As used herein, the terms "top" and "bottom" refer to the relative positions of elements or portions of elements of a hookah device, components of a hookah device, aerosol-generating article, or components of an aerosol-generating article.

The product chamber may be located in the heating unit. The heating unit may comprise an article cavity and an electromagnetic field generator. The heating unit may further comprise one or more of control circuitry, a power supply and an electromagnetic field manipulator, such as a waveguide and an antenna, as described in more detail below. The heating unit may further comprise one or more electrical connectors for electrically connecting one or more electrical components to the heating unit, such as the control circuit, the power supply and the electromagnetic field manipulator.

The heating unit may comprise one or more outer walls formed of a material that is opaque to the RF electromagnetic field. Preferably, all external walls of the heating unit are formed of a material that is opaque to the RF electromagnetic field. The heating unit may comprise an opening to allow insertion of the aerosol-generating article into the article cavity. The heating unit may comprise a movable closure, such as a lid or door, which is movable between an open position and a closed position. The open position may enable insertion of an aerosol-generating article into the article cavity, and the closed position may substantially prevent or inhibit removal of an aerosol-generating article from the article cavity. The movable closure may be movably coupled, e.g. rotatably coupled or slidably coupled, to an outer wall of the heating unit. The movable closure may be removably coupled to the outer wall of the heating unit.

The aerosol-generating device may further comprise a resonant cavity between the article cavity and the electromagnetic field generator. As used herein, the term "resonant cavity" is a structure that can confine electromagnetic waves of a given frequency. In this case, the selected frequency of the electromagnetic wave corresponds to the RF region of the spectrum. To accommodate the electromagnetic waves, the resonant cavity is made of a reflective material (e.g., metal) for that frequency. The structure may be hollow or filled with a dielectric material. The goal of the resonant cavity is to allow electromagnetic waves to bounce back and forth internally in order to enhance the formation of standing waves and minimize power losses.

The resonant cavity amplifies the RF electromagnetic field at a resonant frequency and may be designed to match the impedance of the electromagnetic field generator and the load (in this case, the aerosol-forming substrate in the cavity of the article) in order to optimise the energy absorption of the load and minimise the reflection of radiation from the load. This improves heating efficiency and minimizes radiation leakage from the system. The resonant cavity may be located between the electromagnetic field generator and the article cavity.

The hookah apparatus may include a waveguide. The waveguide can be adjacent to the article cavity. A waveguide may be provided to allow the RF electromagnetic field to enter the article cavity through one or more slots or entry points. The RF radiation may propagate freely within the waveguide. The waveguide may have an outer wall that is opaque to RF electromagnetic radiation. The waveguide may be disposed between the electromagnetic field generator and the article cavity. The waveguide may be arranged between the electromagnetic field generator and the resonant cavity.

The aerosol-generating device may further comprise an antenna connected to the electromagnetic field generator and configured to direct the RF electromagnetic field. The aerosol-generating device may further comprise a plurality of antennas connected to the electromagnetic field generator and configured to direct the RF electromagnetic field. One or more antennas may be positioned at least partially in the article cavity. In use, the one or more antennas may be positioned at least partially in the article cavity with the aerosol-forming substrate. In use, the one or more antennas may be configured to pierce a receptacle or package enclosing the aerosol-forming substrate. One or more antennas may pass through slots in the outer wall of the article cavity. One or more antennas may be coupled to the waveguide. One or more antennas may be coupled to a waveguide coupled to the electromagnetic field generator. One or more antennas may be at least partially disposed in the resonant cavity. The one or more antennas may be disposed between the electromagnetic field generator and the article cavity. The one or more antennas may be disposed between the waveguide and the article cavity. The one or more antennas may be disposed between the waveguide and the resonant cavity.

Providing an antenna to direct the radiation generated by the electromagnetic field generator may improve the efficiency of the device. One or more of the antennas may include conductive pins.

The hookah apparatus may include an air inlet. The air inlet may enable ambient air to be drawn into the hookah apparatus. The device housing of the hookah device may include an air inlet. The air inlet may enable ambient air to be drawn into the article cavity. In embodiments where one or more ends of the article cavity are at an exterior surface of the hookah apparatus, the article cavity may include an air inlet. In embodiments where the article cavity comprises an open end for receiving an aerosol-generating article, the open end may form an air inlet.

An airflow path may be defined between the air inlet and the headspace outlet. The airflow path may extend through the article cavity. The gas flow path may extend from the product chamber into the liquid chamber. The gas flow path may extend from the product chamber into the liquid chamber via a gas flow conduit, below a liquid filling level of the liquid chamber. The gas flow path may extend from below the liquid fill level of the liquid chamber to a headspace of the liquid chamber and out of a headspace outlet.

The airflow path may include one or more meandering portions that extend through the one or more radiation-shielding elements. In embodiments where the airflow path passes through the article cavity or through the generated RF electromagnetic field, the airflow path may include a tortuous portion past one or more radiation shielding elements to prevent RF radiation from escaping through the air inlet or air outlet. One of a plurality of fluid permeable radiation shielding elements may be provided in the airflow path. For example, a metal mesh may be provided in the gas flow path.

In some embodiments, the article cavity is configured such that an air flow path through the article cavity is aligned with the airflow conduit. In some embodiments, the article cavity is configured such that the air flow path through the article cavity is substantially aligned with the direction of the RF electromagnetic field entering the cavity. In some embodiments, the article cavity is configured such that the air flow path through the article cavity is substantially transverse to the direction of the RF electromagnetic field entering the cavity.

In some embodiments, the article cavity includes a first end, a second end opposite the first end, and a side extending between the first end and the second end. In these embodiments, the article cavity may be configured to flow air through the article cavity between the first end and the second end. In these embodiments, the article cavity may be configured to enable RF electromagnetic energy to enter the article cavity at the sides. For example, one or more slots may be provided in the side walls of the article cavity formed of a material that is opaque to RF electromagnetic fields. For example, the sidewalls of the cavity may comprise a material that is substantially transparent to the RF electromagnetic field.

In some embodiments, the article cavity includes a first end, a second end opposite the first end, a first side extending between the first end and the second end, and a second side opposite the first side extending between the first end and the second end. The article cavity may be configured to flow air through the article cavity between the first side and the second side. The article cavity may be configured to enable RF electromagnetic energy to enter the article cavity at least at one of the first end and the second end.

By using RF transistors to generate the RF electromagnetic field, a closed loop control scheme may be used. The hookah apparatus may comprise: a sensor in or adjacent to an article cavity, the sensor providing a signal indicative of a temperature in the article cavity; and a controller connected to receive the signal from the sensor and connected to control the electromagnetic field generator in accordance with the signal from the sensor.

The sensor may comprise a temperature sensor that directly measures temperature. The sensor may include a sampling antenna or antennas configured to detect a disturbance of an electromagnetic field in the article cavity that is indicative of a temperature in the article cavity. The dielectric properties of the aerosol-forming substrate vary depending on the temperature. The frequency or amplitude, or both, of the electromagnetic field may be adjusted by the controller based on signals from the sensor to control the heating provided by the device.

Overheating may be detected by a sensor, and underheating may be detected by a sensor. The frequency and amplitude of the electromagnetic field may be adjusted accordingly depending on whether overheating or underheating is detected. The control circuitry of the hookah apparatus may be configured to adjust at least one of the frequency and the amplitude of the electromagnetic field based on whether the sensor detects overheating or whether the sensor detects overheating.

The fault may be detected by a sensor. If a malfunction is detected, the hookah apparatus may automatically shut down. The presence of inappropriate materials in the product cavity can also be detected. The hookah apparatus may be automatically shut off if an improper material in the article cavity is detected. Similarly, the device may be automatically switched off if the signal for the sensor indicates that no aerosol-forming substrate is present in the article cavity. To automatically turn off the hookah apparatus, the control circuit of the hookah apparatus may be configured to prevent power from being supplied to the electromagnetic field generator. Such control is not possible if a magnetron is used to generate the RF radiation.

It may be desirable to maintain the temperature within the product cavity within a predetermined temperature range. It may be desirable to maintain the temperature of the aerosol-forming substrate below the temperature at which the aerosol-forming substrate burns.

The ability to control the amount of heating provided by the hookah apparatus based on the feedback signal also allows different aerosol-forming substrates to be used. Different aerosol-forming substrates may be desired to be heated to different temperatures. Thus, the mechanism that provides temperature control allows optimal conditions to be achieved for different aerosol-forming substrates or different aerosol-forming article designs.

The hookah apparatus may include a puff detector configured to detect when a user puffs on the hookah apparatus. As used herein, the term "puff" is used to refer to a user puffing on a hookah apparatus to receive an aerosol. The puff detector may include a temperature sensor. The puff detector may comprise a pressure sensor. The puff detector may include both a temperature sensor and a pressure sensor.

The hookah apparatus may include a control circuit. The control circuit may be configured to control the supply of power to the electromagnetic field generator. The control circuitry may include one or more of a microprocessor, a programmable microprocessor, a microcontroller, and an Application Specific Integrated Chip (ASIC) or other electronic circuitry capable of providing control. The control circuitry may include other electronic components. For example, in some embodiments, the control circuitry may include one or more of sensors, switches, and display elements. The control circuit may include an RF power sensor. The control circuit may include a power amplifier.

In some embodiments, the hookah apparatus is configured to be connected to an external power source. For example, the hookah apparatus may be configured to connect to a mains power supply.

In some embodiments, the hookah apparatus includes a power source. The power supply may be a DC power supply. The power supply may typically include a battery or another form of charge storage device, such as a capacitor. The power source may include a rechargeable lithium ion battery. In some embodiments, the power source is a rechargeable power source. The hookah apparatus may be configured to be connected to an external power source for charging a rechargeable power source.

The control circuit may be configured to control the supply of power from the power source to the electromagnetic field generator.

The power source may provide between about 0.5 watts and about 50 watts of power. In some embodiments, the power source may provide between about 1 watt and about 40 watts, or between about 2 watts and about 30 watts of power.

Where the electro-magnetic field generator is a solid state RF transistor, the impedance of the electro-magnetic field generator may be less than or equal to about 100 ohms. The impedance of the electromagnetic field generator may be less than or equal to 75 ohms. The impedance of the electromagnetic field generator may be greater than about 1 ohm. The impedance of the electromagnetic field generator may be greater than about 10 ohms. The impedance of the electromagnetic field generator may be between 50 ohms and 75 ohms.

Where the electro-magnetic field generator is a solid state RF transistor, the forward voltage across the electro-magnetic field generator may be less than or equal to about 100 volts. The forward voltage across the electromagnetic field generator may be greater than or equal to about 1 volt. The forward voltage across the electromagnetic field generator may be between about 1 volt and about 100 volts.

The hookah apparatus may include a container. The liquid chamber may be an interior volume of the container. The container may be configured to contain a liquid. The container may define a liquid chamber. The vessel includes a headspace outlet. The container may define a liquid fill level. For example, the container may include a liquid fill level definition. The liquid fill level definition is an indicator provided on the container that indicates a desired level of liquid that the liquid chamber is expected to be filled with liquid. The headspace outlet may be arranged above the liquid fill level. The headspace outlet may be arranged above the liquid fill level limit. The container may include an optically transparent portion. The optically transparent portion may enable a user to view the contents contained in the container. The container may be formed of any suitable material. For example, the container may be formed from glass or a rigid plastic material. In some embodiments, the container is removable from the remainder of the hookah assembly. In some embodiments, the container is removable from the aerosol-generating portion of the hookah assembly. Advantageously, the removable container enables a user to fill the liquid chamber with liquid, empty the liquid chamber of liquid, and clean the container.

The container may be filled to a liquid fill level by a user. The liquid preferably comprises water. The liquid may include water infused with one or more of a coloring agent and a flavoring agent. For example, water may be injected with one or both of the plant and herbal infusions.

The container may have any suitable shape and size. The fluid chamber may have any suitable shape and size. The headspace can have any suitable shape and size.

Generally, a hookah apparatus according to the present disclosure is intended to be placed on a surface in use, rather than being carried by a user. Thus, a hookah device according to the present disclosure may have a particular use orientation or range of orientations in which the device is intended to be oriented during use. Thus, as used herein, the terms "above" and "below" refer to the relative positions of features of a hookah apparatus or hookah system when the hookah apparatus or hookah system is held in a use orientation.

In some embodiments, the article cavity is disposed above the liquid cavity. In these embodiments, the air flow conduit may extend from the product chamber to below the liquid fill level of the liquid chamber. Advantageously, this may ensure that volatile compounds released from the aerosol-forming substrate in the article cavity are delivered from the article cavity to the volume of liquid in the liquid cavity, rather than the headspace above the liquid cavity. In these embodiments, the gas flow conduit may extend from the aerosol chamber into the liquid chamber through a headspace in the liquid chamber above a liquid fill level, and into a volume of liquid below the liquid fill level. The gas flow conduit may extend into the liquid chamber through a top or upper end of the liquid chamber.

In some embodiments, the article chamber is disposed below the liquid chamber. In these embodiments, a one-way valve may be disposed between the article chamber and the liquid chamber. The one-way valve prevents liquid from the liquid chamber from entering the product chamber under the influence of gravity. In these embodiments, the one-way valve may be disposed in an air flow conduit extending from the product chamber into the liquid chamber. In these embodiments, the gas flow conduit may extend below the liquid fill level in the liquid chamber. The gas flow conduit may extend into the liquid chamber through a bottom end of the liquid chamber.

According to some particularly preferred embodiments of the present disclosure, there is provided a hookah apparatus for heating an aerosol-forming substrate to generate an aerosol, the hookah apparatus comprising: a liquid chamber containing a volume of liquid, the liquid chamber having a headspace outlet; an article cavity configured to receive an aerosol-forming substrate, the article cavity being in fluid communication with the liquid cavity; and an electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article cavity, the electromagnetic field generator comprising a solid state RF transistor.

According to some particularly preferred embodiments of the present disclosure, there is provided a hookah apparatus for heating an aerosol-forming substrate to generate an aerosol, the hookah apparatus comprising: a liquid chamber configured to contain a volume of liquid, the liquid chamber having a headspace outlet; an article cavity configured to receive an aerosol-forming substrate; an air flow conduit extending between the product chamber and the liquid chamber, the air flow conduit fluidly connecting the product chamber and the liquid chamber; a mouthpiece fluidly connected to a headspace outlet of the liquid chamber; and an electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article cavity.

According to some particularly preferred embodiments of the present disclosure, there is provided a hookah apparatus for heating an aerosol-forming substrate to generate an aerosol, the hookah apparatus comprising: a liquid chamber configured to contain a volume of liquid, the liquid chamber having a headspace outlet; a heating unit comprising an article cavity configured to receive an aerosol-forming substrate, and an outer housing formed from a material that is opaque to an RF electromagnetic field; an air flow conduit extending between the product chamber and the liquid chamber, the air flow conduit fluidly connecting the product chamber and the liquid chamber; a mouthpiece fluidly connected to a headspace outlet of the liquid chamber; and an electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article cavity.

In the present disclosure there is also provided an aerosol-generating article for use with a hookah apparatus as previously described.

The aerosol-generating article may be any suitable type of aerosol-generating article for use with a hookah apparatus. Aerosol-generating articles specifically designed for use with hookah devices may be referred to as cartridges of hookah devices. An aerosol-generating article specifically designed for use with a hookah apparatus having an electromagnetic field generator may be referred to as a cartridge of a hookah apparatus having an electromagnetic field generator.

The aerosol-generating article may have any suitable shape and size. In particular, the aerosol-generating article may have a shape and size complementary to the article cavity of the hookah apparatus.

The aerosol-generating article may have any suitable cross-section. For example, the aerosol-generating article may have a circular, oval, rectangular, square, triangular, or any other polygonal cross-sectional shape.

In some embodiments, the aerosol-generating article is substantially cylindrical.

In some embodiments, the aerosol-generating article is substantially frustoconical. In some embodiments, the width or diameter of a first end of the aerosol-generating article is greater than the width or diameter of a second end of the aerosol-generating article opposite the first end. In other words, the aerosol-generating article may taper from the first end to the second end. Providing the aerosol-generating article with a second end that is narrower than the first end may enable the aerosol-generating article to be retained in a complementary article cavity under the influence of gravity.

The aerosol-generating article may have a length of between about 10 millimeters and about 100 millimeters, a length of between about 20 millimeters and about 90 millimeters, or a length of between about 25 millimeters and about 80 millimeters. In some preferred embodiments, the aerosol-generating article may have a length of about 33 mm, about 34 mm, about 35 mm, about 36 mm, about 37 mm, about 38 mm, 39 mm, about 40 mm, about 41 mm or about 42 mm. The aerosol-generating article may have a width or diameter of between about 5 mm and about 70 mm, or a width or diameter of between about 10 mm and about 60 mm, or a width or diameter of between about 10 mm and about 50 mm. In some preferred embodiments, the aerosol-generating article may have a width or diameter of about 35 mm, about 36 mm, about 37 mm, about 38 mm, 39 mm, about 40 mm, about 41 mm, about 42 mm, about 43 mm, about 44 mm or about 45 mm.

The aerosol-generating article comprises an aerosol-forming substrate. The aerosol-forming substrate may be enclosed in a wrapper or receptacle. In some embodiments, the aerosol-forming substrate may be coated with a coating.

The wrapper may define a substrate cavity. The aerosol-forming substrate may be positioned in a substrate cavity within a package.

In some embodiments, the package may comprise a material that is opaque to the RF electromagnetic field. In some embodiments, at least a portion of the package comprises a material that is opaque to RF electromagnetic fields. In some embodiments, the entire package may comprise a material that is opaque to RF electromagnetic fields.

One or more slots may be formed in the package to allow the RF electromagnetic field to enter the aerosol-forming substrate. In particular, where the entire package comprises a material that is opaque to RF electromagnetic fields, one or more slots may be formed in the package to allow the electromagnetic fields to enter the aerosol-forming substrate.

At least a portion of the wrapper may be fluid permeable. The fluid permeable portion of the wrapper may enable the volatile compounds released from the aerosol-forming substrate to be released from the aerosol-generating article. A portion of the package comprising a material that is opaque to the RF electromagnetic field may also be fluid permeable. For example, the fluid permeable material that is impermeable to RF electromagnetic fields may be a metal mesh. Thus, at least a portion of the wrapper may be formed from a metal mesh. In some embodiments, the wrapper may be formed from a metal mesh.

The liquid aerosol-forming substrate may be enclosed in a receptacle. The receptacle may define a substrate cavity. The aerosol-forming substrate may be positioned in a substrate cavity within the receptacle.

In some embodiments, the receptacle may comprise a material that is opaque to RF electromagnetic fields.

In some embodiments, the receptacle may include one or more walls. At least one wall of the receptacle may comprise a material that is opaque to RF electromagnetic fields. All walls of the receptacle may comprise a material that is opaque to RF electromagnetic fields.

The receptacle includes a top wall, a bottom wall, and a side wall extending between the top wall and the bottom wall. The top wall may be constructed of a material that is opaque to RF electromagnetic fields. The bottom wall may be constructed of a material that is opaque to RF electromagnetic fields. The sidewalls may be constructed of a material that is opaque to RF electromagnetic fields. In some embodiments, the top wall, the bottom wall, and the side walls each comprise a material that is opaque to RF electromagnetic fields.

One or more slots may be formed in the receptacle to allow entry of the RF electromagnetic field. In particular, where the top, bottom and side walls of the receptacle each comprise a material that is opaque to the RF electromagnetic field, one or more slots may be formed in the receptacle to allow the RF electromagnetic field to enter the aerosol-forming substrate.

In some embodiments including a receptacle, the top and bottom walls of the receptacle comprise a material that is opaque to RF electromagnetic fields. In some of these embodiments, the sidewall does not include a material that is opaque to the RF electromagnetic field to enable RF electromagnetic field to enter at the sidewall.

In some embodiments including a receptacle, the sidewall of the receptacle comprises a material that is opaque to RF electromagnetic fields. In some of these embodiments, the top wall comprises a material that is opaque to the RF electromagnetic field and the bottom wall does not comprise a material that is opaque to the RF electromagnetic field to enable RF electromagnetic field to enter at the bottom wall. In some of these embodiments, the bottom wall comprises a material that is opaque to the RF electromagnetic field and the top wall does not comprise a material that is opaque to the RF electromagnetic field to enable the RF electromagnetic field to enter at the top wall.

In some embodiments including a receptacle wherein the top wall, bottom wall and side walls each comprise a material that is opaque to RF electromagnetic fields, one or more slots are formed in the walls of the receptacle to allow entry of the electromagnetic fields. In some of these embodiments, one or more slots are formed in the top wall. In some of these embodiments, one or more slots are formed in the bottom wall. In some of these embodiments, one or more slots are formed in the sidewall.

At least a portion of the receptacle may be fluid permeable. The fluid permeable portion of the receptacle may enable volatile compounds released from the aerosol-forming substrate to be released from the aerosol-generating article. The walls of the receptacle comprising a material that is opaque to the RF electromagnetic field may also be fluid permeable. For example, the fluid permeable material that is impermeable to RF electromagnetic fields may be a metal mesh. Thus, at least a portion of the receptacle may be formed from expanded metal. In some embodiments, the receptacle may be formed from a metal mesh.

In some embodiments, at least a portion of the aerosol-forming substrate is coated with a coating. As used herein, the term "coating" refers to a layer of material that covers and adheres to an aerosol-forming substrate. The coating may be applied to cover and adhere to at least a portion of the aerosol-forming substrate by any suitable method known in the art, including but not limited to spraying, vapour deposition, dipping, material transfer (e.g. brushing or gluing), electrostatic deposition, or any combination thereof.

In some embodiments, the coating may comprise a material that is opaque to RF electromagnetic fields.

One or more regions of the outer surface of the aerosol-forming substrate may be exposed. In other words, one or more regions of the outer surface of the aerosol-forming substrate may be free of any coating. This may ensure that volatile compounds released from the aerosol-forming substrate are able to escape from the aerosol-generating article. This may also enable the RF electromagnetic field to enter the aerosol-forming substrate when the coating comprises a material that is opaque to the RF electromagnetic field.

In some embodiments, the coating may comprise a fluid permeable material.

In some embodiments, one or more regions of the outer surface of the aerosol-forming substrate may be coated with a first coating and one or more regions of the outer surface of the aerosol-forming substrate may be coated with a second coating. One of the first coating and the second coating may comprise a material that is opaque to RF electromagnetic fields. One of the first coating and the second coating may comprise a fluid permeable material. In some preferred embodiments, one of the first coating and the second coating comprises a material that is opaque to RF electromagnetic fields and the other of the first coating and the second coating comprises a fluid permeable material. This may enable the RF electromagnetic field to enter the aerosol-forming substrate at one region of the aerosol-forming substrate and may enable air to be drawn through the aerosol-forming substrate at another region of the aerosol-forming substrate without the RF electromagnetic field exiting from the aerosol-forming substrate at that region.

In some embodiments, at least a portion of the wrapper or receptacle enclosing the aerosol-forming substrate is coated with a coating. The coating may comprise a material that is opaque to RF electromagnetic fields.

The aerosol-forming substrate may be any suitable substrate which is capable of releasing a volatile compound on heating.

In some preferred embodiments, the aerosol-forming substrate is in the form of a suspension. For example, the aerosol-forming substrate may comprise molasses. As used herein, "molasses" refers to an aerosol-forming substrate composition comprising a suspension having at least about 20% by weight of sugar. For example, the molasses may include at least about 25% by weight sugar, such as at least about 35% by weight sugar. Typically, the molasses will contain less than about 60% by weight sugar, such as less than about 50% by weight sugar.

Preferably, the aerosol-forming substrate is a hookah substrate. As used herein, "hookah substrate" refers to an aerosol-forming substrate composition comprising at least about 20% by weight sugar. The hookah base may include molasses. The hookah substrate may include a suspension having at least about 20% by weight sugar.

The aerosol-forming substrate may be solid or liquid, or comprise solid and liquid components.

The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may comprise a nicotine salt substrate. The aerosol-forming substrate may comprise a plant based material. The aerosol-forming substrate preferably comprises tobacco. The tobacco-containing material preferably contains volatile tobacco flavour compounds which are released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise a homogenized tobacco material. Homogenized tobacco material may be formed by agglomerating particulate tobacco. The aerosol-forming substrate may comprise a non-tobacco containing material. The aerosol-forming substrate may comprise a homogenized plant-based material.

The aerosol-forming substrate may comprise, for example, one or more of: powder, granule, chip, spaghetti, strip or sheet. The aerosol-forming substrate may contain one or more of the following: herbal leaf, tobacco vein segment, reconstituted tobacco, homogenized tobacco, extruded tobacco, and expanded tobacco. The tobacco may be cured.

The aerosol-forming substrate may comprise at least one aerosol-former. Suitable aerosol-forming agents include compounds or mixtures of compounds which, in use, facilitate the formation of a dense and stable aerosol and are substantially resistant to thermal degradation at the operating temperatures of the hookah apparatus. Suitable aerosol-forming agents are well known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, 1, 3-butanediol, and glycerin; esters of polyhydric alcohols such as monoacetin, diacetin, or triacetin; and fatty acid esters of monocarboxylic, dicarboxylic or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Particularly preferred aerosol formers are polyols or mixtures thereof, such as triethylene glycol, 1, 3-butanediol and most preferably glycerol. The aerosol former may be propylene glycol. The aerosol-forming substrate may comprise any suitable amount of aerosol-former. For example, the aerosol former content of the substrate may be equal to or greater than 5% by dry weight, and preferably greater than 30% by weight by dry weight. The aerosol former content may be less than about 95% by dry weight. Preferably, the aerosol former content is up to about 55% by dry weight.

The aerosol-forming substrate preferably comprises nicotine and at least one aerosol former. In some embodiments, the aerosol former is glycerin or a mixture of glycerin and one or more other suitable aerosol formers, such as those listed above. In some example embodiments, the aerosol former is propylene glycol.

The aerosol-forming substrate may comprise other additives and ingredients, such as flavourants. In some examples, the aerosol-forming substrate comprises any suitable amount of one or more sugars. Preferably, the aerosol-forming substrate comprises invert sugar. Invert sugar is a mixture of glucose and fructose obtained by splitting sucrose. Preferably, the aerosol-forming substrate comprises from about 1% to about 40% by weight of a sugar, such as invert sugar. In some examples, one or more sugars can be mixed with a suitable carrier such as corn starch or maltodextrin.

In some examples, the aerosol-forming substrate comprises one or more sensory enhancers. Suitable sensory enhancers include flavors and sensates, such as cooling agents. Suitable flavoring agents include natural or synthetic menthol, peppermint, spearmint, coffee, tea, spices (such as cinnamon, clove, ginger, or combinations thereof), cocoa, vanilla, fruit flavors, chocolate, eucalyptus, geranium, eugenol, agave, juniper, anethole, linalool, and any combinations thereof.

Any suitable amount of aerosol-forming substrate (e.g. molasses or tobacco substrate) may be provided in the aerosol-generating article. In some preferred embodiments, from about 3 grams to about 25 grams of aerosol-forming substrate is provided in an aerosol-generating article. The cartridge may comprise at least 6g, at least 7g, at least 8g or at least 9g of aerosol-forming substrate. The cartridge may comprise at most 15g, at most 12g, at most 11g, or at most 10g of aerosol-forming substrate. Preferably, from about 7 grams to about 13 grams of aerosol-forming substrate is provided in the aerosol-generating article.

The aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The term "thermally stable" as used herein refers to a material that does not substantially degrade at the temperature to which the matrix is typically heated (e.g., about 150 ℃ to about 300 ℃). The support may comprise a thin layer on which the substrate is deposited on the first major surface, the second major outer surface, or both the first major surface and the second major surface. The carrier may be formed from, for example, paper or paper-like material, a non-woven carbon fibre mat, a low mass open mesh metal screen, or a perforated metal foil or any other thermally stable polymer matrix. Alternatively, the carrier may be in the form of a powder, granules, pellets, chips, strands, ribbons, or sheets. The carrier may be a nonwoven fabric or a tow of fibers into which the tobacco component has been incorporated. The nonwoven fabric or fiber bundle may comprise, for example, carbon fibers, natural cellulose fibers, or cellulose derivative fibers.

In some preferred embodiments, the aerosol-forming substrate may comprise tobacco, sugar and an aerosol former. In these embodiments, the aerosol-forming substrate may comprise from 10% to 40% by weight of tobacco. In these embodiments, the aerosol-forming substrate may comprise 20% to 50% by weight of the sugar. In these embodiments, the aerosol-forming substrate may comprise from 25% to 55% by weight of the aerosol-former. In some particularly preferred embodiments, the aerosol-forming substrate comprises 20 to 30% by weight tobacco, 30 to 40% by weight sugar, 35 to 45% by weight aerosol former. In some particularly preferred embodiments, the aerosol-forming substrate may comprise about 25% by weight tobacco, about 35% by weight sugar and about 40% by weight aerosol former. In these preferred embodiments, the tobacco may be flue-cured tobacco leaf. In these preferred embodiments, the sugar may be sucrose or invert sugar. In these preferred embodiments, the aerosol former may be propylene glycol.

According to some particularly preferred embodiments of the present disclosure, there is provided an aerosol-generating article for a hookah system, the aerosol-generating article comprising: an aerosol-forming substrate composition comprising a suspension having at least about 20% by weight of sugar; and one or more external surfaces formed of a material that is opaque to RF electromagnetic fields.

According to some particularly preferred embodiments of the present disclosure, there is provided an aerosol-generating article for a hookah system, the aerosol-generating article comprising: an aerosol-forming substrate; and a coating applied to at least a portion of an outer surface of an aerosol-forming substrate formed from a material that is opaque to RF electromagnetic fields.

According to some particularly preferred embodiments of the present disclosure, there is provided an aerosol-generating article for a hookah system, the aerosol-generating article comprising: an aerosol-forming substrate; and a wrapper surrounding the aerosol-forming substrate, the wrapper comprising one or more fluid permeable regions and one or more regions formed from a material which is opaque to RF electromagnetic fields.

In the present disclosure there is provided a hookah system comprising a hookah apparatus as hereinbefore described and an aerosol generating article comprising an aerosol-forming substrate.

In particular, in the present disclosure there is provided a hookah system comprising a hookah apparatus as previously described and an aerosol-generating article as previously described.

In particular, in the present disclosure, a hookah system is provided that includes a hookah apparatus and an aerosol-generating article. The hookah apparatus comprising: a liquid chamber configured to contain a volume of liquid; the liquid chamber having a headspace outlet; an article cavity configured to receive an aerosol-forming substrate, the article cavity being in fluid communication with the liquid cavity; and an electromagnetic field generator configured to generate a Radio Frequency (RF) electromagnetic field in the article cavity. An aerosol-generating article comprises an aerosol-forming substrate.

In some of these embodiments, the article cavity comprises one or more walls formed of a material that is opaque to RF electromagnetic fields, and an opening that enables insertion of the aerosol-generating article into the article cavity. In these embodiments, the aerosol-generating article may comprise an outer surface formed from a material that is opaque to RF electromagnetic fields. The external surface of the aerosol-generating article may be configured such that, when the aerosol-generating article is received in the article cavity, one or more walls of the article cavity formed from a material that is opaque to said RF electromagnetic field align with the external surface of the aerosol-generating article formed from a material that is opaque to said RF electromagnetic field to form a closure around the aerosol-forming substrate, the closure being bounded by the surface formed from the material that is opaque to said RF electromagnetic field.

It will be appreciated that features described in relation to a hookah apparatus or aerosol-generating article may also be applicable to a hookah system according to the present disclosure.

It should also be appreciated that particular combinations of the various features described above can be implemented, provided and used independently.

Drawings

Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a dielectric heating system;

FIG. 2 is a schematic diagram of a closed loop control system for a hookah system having a dielectric heating system according to an embodiment of the present disclosure;

FIG. 3 is a schematic view of an embodiment of a hookah system having a dielectric heating system;

figure 4 is a schematic view of a heating unit of a hookah apparatus and an aerosol generating article configured for use with the hookah apparatus according to embodiments of the present disclosure;

FIG. 5 is a schematic view of a heating unit of various embodiments of a hookah apparatus according to embodiments of the present disclosure;

figure 6 is a schematic view of a heating unit of a hookah apparatus and an aerosol generating article configured for use with the hookah apparatus according to embodiments of the present disclosure;

figure 7 is a schematic view of a heating unit of a hookah apparatus and an aerosol generating article configured for use with the hookah apparatus according to embodiments of the present disclosure;

figure 8 is a schematic view of a heating unit of a hookah apparatus and an aerosol generating article configured for use with the hookah apparatus according to embodiments of the present disclosure; and

figure 9 is a schematic view of an embodiment of a hookah system having a dielectric heating system.

Detailed Description

FIG. 1 is a schematic diagram of a system for heating using Radio Frequency (RF) electromagnetic radiation, sometimes referred to as dielectric heating. The system includes a radiofrequency signal generator 10, apower amplifier 12 connected to the signal generator to amplify the radio frequency signal, and anantenna 16 positioned inside thearticle cavity 14, theantenna 16 being connected to an output of thepower amplifier 12. The output of thepower amplifier 12 is fed back to thesignal generator 10 to provide closed loop control. Anarticle 18 to be heated is placed in thearticle cavity 14 and subjected to radio frequency electromagnetic radiation. Polar molecules within thearticle 18 are aligned with the oscillating electromagnetic field and are therefore perturbed by the electromagnetic field as it oscillates. This results in an increase in the temperature of thearticle 18. Such heating has the advantage of being uniform throughout the article (provided that the polar molecules are uniformly distributed). It also has the advantage of being a form of non-contact heating that does not require conduction or convection of heat from the high temperature heating element.

Fig. 2 shows a control scheme that may be used in any of the embodiments described in fig. 3 to 9. As previously described, the system includes a control circuit for the electromagnetic field generator. In the example of fig. 2, theelectromagnetic field generator 11 comprises a solid-state RF LDMOS transistor that performs the functions of both theRF signal generator 10 and thepower amplifier 12 to amplify the generated RF electromagnetic signal. The output of the RF solid state transistor is passed to a radiatingantenna 16 positioned to radiate an aerosol-formingsubstrate 20 located within an aerosol-generatingarticle 18 received in thearticle cavity 14.

The control circuit includes amicrocontroller 26 that can control both the frequency and power output of the RF solid-state transistor. One or more sensors provide inputs to themicrocontroller 26. Themicrocontroller 26 adjusts the frequency or power output, or both, of theelectromagnetic field generator 11 based on the sensor input. In the example shown in fig. 2, there is atemperature sensor 28 positioned to sense the temperature within theproduct cavity 14. Thesampling antenna 30 may be disposed in thearticle cavity 14 as an alternative or in addition to thetemperature sensor 28. Thesampling antenna 30 is configured as a receiver and may detect perturbations of the electromagnetic field in thearticle cavity 14, which is indicative of the efficiency with which energy is absorbed by the aerosol-formingsubstrate 20. AnRF power sensor 32 is also provided to detect the power output from theelectromagnetic field generator 11.

Themicrocontroller 26 receives signals from theRF power sensor 32, thetemperature sensor 28, and thesampling antenna 30. The signal may be used to determine at least one among: whether the temperature is too low, whether the temperature is too high, whether there is a fault, and whether there is no matrix or a matrix with inadequate dielectric properties in thearticle cavity 14.

Based on the determination made by themicrocontroller 26, the frequency and power of the electromagnetic field generated by the RF solid-state transistor is adjusted, or the electromagnetic field is turned off. Generally, it is desirable to provide a stable and consistent volume of aerosol, which means that the aerosol-forming substrate is maintained within a particular temperature range. However, as the composition of the aerosol-forming substrate changes and the temperature of the surrounding system changes, the desired target temperature may vary over time. Furthermore, the dielectric properties of the aerosol-forming substrate vary with temperature and therefore the electromagnetic field may need to be adjusted as the temperature increases or decreases.

It should be clear that features described in relation to one embodiment may also be applied to other embodiments. The described embodiments provide the advantage of uniform, non-contact heating of the aerosol-forming substrate in a manner that can be controlled to provide specific, desired aerosol characteristics. The use of solid state RF transistors also allows for better control of frequency and power and longer operating life than conventional microwave heating using magnetrons.

The embodiment described with reference to figures 3 to 8 uses the basic heating and control principle shown in figures 1 and 2. In addition, the embodiments described with reference to fig. 3-8 use solid-state Radio Frequency (RF) transistors to perform the signal generation and power amplification functions shown in fig. 1. However, it is possible to implement the described embodiments using RF transistors for signal generation and a separate electronic component or components for providing power amplification. It is also possible to implement the described embodiments using conventional microwave heating systems, for example systems using magnetrons.

Figure 3 is a schematic diagram of a hookah system according to an embodiment of the present disclosure.

Thehookah apparatus 50 includes acontainer 52 defining aliquid chamber 54. Thecontainer 52 is configured to retain a volume of liquid in theliquid chamber 54 and is formed of a rigid optically transparent material, such as glass. In this embodiment, thecontainer 52 has a generally frusto-conical shape and is supported at its wide end in use on a flat horizontal surface such as a stand or shelf. Theliquid chamber 54 is divided into two sections, aliquid section 56 for receiving a volume of liquid and aheadspace 58 above theliquid section 58. Aliquid fill level 60 is positioned at the boundary between theliquid section 56 and theheadspace 58, theliquid fill level 60 being defined on thecontainer 52 by the dashed line marked on the outer surface of thecontainer 52. Aheadspace outlet 62 is provided in the sidewall of thecontainer 52 above theliquid fill level 60. Theheadspace outlet 62 enables fluid to be drawn from theheadspace 58 out of theliquid cavity 54. Themouthpiece 64 is connected to theheadspace outlet 62 by aflexible hose 66. A user may draw on themouthpiece 64 to draw fluid out of thetop space 58 for inhalation.

Thehookah apparatus 50 further comprises aheating unit 70 comprising an electromagnetic field generator according to the present disclosure. Examples of different heating units will be discussed in more detail below with reference to fig. 4, 5, 6, 7 and 8. Theheating unit 70 is disposed above thecontainer 52 by anairflow conduit 72. In this embodiment, theheating unit 70 is supported above thecontainer 52 by anairflow conduit 72, however, it should be appreciated that in other embodiments, theheating unit 70 may be supported above thecontainer 52 by the housing of the hookah apparatus or another suitable support. Anair flow conduit 72 extends from theheating unit 70 into theliquid chamber 54 of thecontainer 52. Thegas flow conduit 72 extends through theheadspace 58 and into theliquid section 58 below theliquid fill level 60. Thegas flow conduit 72 includes anoutlet 74 below theliquid fill level 60 in theliquid section 56 of theliquid chamber 54. This arrangement enables air to be drawn from theheating unit 70 to themouthpiece 64. Air may be drawn from the environment outside thedevice 50 into theheating unit 70, through theheating unit 70, into the volume of liquid in theliquid section 56 of theliquid chamber 54 through theairflow conduit 72, out of the volume of liquid into theheadspace 58, out of the container from theheadspace 58 at theheadspace outlet 62, through thehose 66 to themouthpiece 64.

In use, a user may draw on themouthpiece 64 of thehookah device 50 to receive aerosol from thehookah device 50. In more detail, an aerosol-generating article comprising an aerosol-forming substrate may be positioned in an article cavity within theheating unit 70 of thehookah apparatus 50. Theheating unit 70 is operable to heat an aerosol-forming substrate within an aerosol-generating article and release volatile compounds from the heated aerosol-forming substrate. When a user draws on themouthpiece 64 of thehookah device 50, the pressure within thehookah device 50 is reduced, which draws volatile compounds released from the aerosol-forming substrate out of theheating unit 70 and into theairflow conduit 72. The volatile compounds are drawn out of theairflow conduit 72 at theoutlet 74 and into the volume of liquid in theliquid section 56 of theliquid chamber 54. The volatile compounds cool in a volume of liquid and are released into theheadspace 58 above theliquid fill level 60. The volatile compounds in theheadspace 58 condense to form an aerosol which is drawn from the headspace at theheadspace outlet 62 and to themouthpiece 64 for inhalation by the user.

Figure 4 shows a schematic illustration of a combination of aheating unit 70 and an aerosol-generatingarticle 90 of thehookah apparatus 50 of figure 3 forming a hookah system, according to embodiments of the present disclosure. Figure 4a shows theheating unit 70 and aerosol-generatingarticle 90 prior to insertion of the aerosol-generatingarticle 90 into thearticle cavity 14 of theheating unit 70. Figure 4b shows an aerosol-generatingarticle 90 received in thearticle cavity 14 of theheating unit 70.

As shown in fig. 4a, theheating unit 70 comprises anouter housing 71. Theouter housing 71 forms a cylindrical tube which is open at one end for insertion of the aerosol-generatingarticle 90 and substantially closed at the opposite end. Theouter housing 71 is formed of a material opaque to RF electromagnetic radiation, such as aluminum.

Theproduct chamber 14 is defined within theouter housing 71 by abase 78 and asidewall 76 that extends between the periphery of thebase 78 and the open end of theouter housing 71. Thearticle cavity 14 is configured to receive an aerosol-generatingarticle 90 and has a shape and size complementary to the aerosol-generatingarticle 90. The diameter of thebase 78 of theproduct chamber 14 is smaller than the diameter of the open end of theouter housing 71 so that theside wall 76 is inclined relative to the cylindrical side wall of theouter housing 71. Thus, thearticle cavity 14 has a substantially frustoconical shape which is open at its wide end to receive the aerosol-generatingarticle 90. Theside walls 76 and thebase 78 of thearticle cavity 14 are formed of a material that is opaque to RF electromagnetic radiation, such as aluminum. However, thebase 78 of thearticle cavity 14 includes a plurality ofslots 79 configured to enable the RF electromagnetic field to propagate into thearticle cavity 14 via thebase 78.

Theresonant cavity 80 is located below thebase 78 of theproduct chamber 14. In this embodiment, theresonant cavity 80 is defined between the base 78 of thearticle cavity 14, the substantially closed end of theouter shell 71, and theinner wall 82. Theinner wall 82 extends between the periphery of thebase 78 of theproduct chamber 14 and the substantially closed end of theouter shell 71. In this embodiment, theinner wall 82 is formed of a material that is opaque to RF electromagnetic radiation, such as aluminum.

It should be understood that in other embodiments, the position of theinner wall 82 may be varied to vary the size and shape of theresonant cavity 80. It may be necessary to change the position of theinner wall 82 to enable an electromagnetic field of a particular frequency to resonate within theresonant cavity 80.

Preferably, thebase 78 and sidewalls 76 of thearticle cavity 14 and theinner walls 82 andouter housing 71 have polished surfaces to improve reflection of the RF radiation.

Theheating unit 70 further comprises anelectromagnetic field generator 11. Theelectromagnetic field generator 11 comprises a solid-state RF LDMOS transistor that performs the function of both an RF signal generator and a power amplifier to amplify the generated RF electromagnetic signal. The output of the RF solid-state transistor is coupled to awaveguide 15. Thewaveguide 15 extends into theresonant cavity 80 through the substantially closed end of theouter housing 71. Thewaveguide 15 is coupled to anantenna 16 positioned within theresonant cavity 80 and configured to radiate an RF electromagnetic field generated by the RF solid state transistor into theresonant cavity 80.

Theelectromagnetic field generator 11 is connected to a power source (not shown) of the hookah apparatus and to a control circuit (not shown) configured to control the supply of power from the power source to theelectromagnetic field generator 11. In this embodiment, the power source is a rechargeable lithium ion battery and thehookah apparatus 50 includes a power connector that enables thehookah apparatus 50 to be connected to a mains power source for recharging the power source. Providing thehookah apparatus 50 with a power source, such as a battery, enables thehookah apparatus 50 to be portable and used outdoors or in locations where mains power is unavailable.

Theheating unit 70 is disposed above thecontainer 52 of thehookah apparatus 50 by anairflow conduit 72. Theair flow conduit 72 is fixedly attached to the substantially closed end of theouter housing 71 of theheating unit 70. It should be understood that in other embodiments, theheating unit 70 may be removably attached to theairflow conduit 72 such that theheating unit 70 may be removed for cleaning or replacement, if necessary. Anopening 73 is provided in the substantially closed end of theouter housing 71 to fluidly connect theresonant cavity 80 to thegas flow conduit 72. A radiation-shielding element (not shown) in the form of a metallic mesh is disposed over the opening 73 of theouter housing 71 to substantially prevent the RF electromagnetic field from exiting theresonant cavity 80 into theairflow conduit 72 without substantially affecting the fluid flow between theresonant cavity 80 and theairflow conduit 72.

Thus, theheating unit 70 is configured such that air may be drawn from theproduct chamber 14 into theresonant chamber 80, through theslot 79 in thebase 78, and from theresonant chamber 80 into theairflow conduit 72 through theopening 73 and the radiation-shielding element.

The aerosol-generatingarticle 90 comprises an aerosol-formingsubstrate 92. In this embodiment, the aerosol-formingsubstrate 92 is a hookah substrate comprising molasses and tobacco. An aerosol-formingsubstrate 92 is housed within the receptacle. The receptacle has a substantially frustoconical shape complementary to the shape of theproduct chamber 14. The receptacle includes abottom wall 94, atop wall 96 and aside wall 98 extending between thebottom wall 94 and thetop wall 96. Thebottom wall 94 andside walls 98 of the receptacle are formed of a material that is permeable to fluids and substantially permeable to RF electromagnetic fields, such as a perforated paperboard or plastic material. This enables air to be drawn into or removed from the aerosol-generating article through thebottom wall 94 and theside wall 98, and the RF electromagnetic field to enter the aerosol-generating article through thebottom wall 94 and theside wall 98. Thetop wall 96 comprises a material that is opaque to RF electromagnetic fields, such as a metal mesh. This causes air to be drawn into the aerosol-generating article through thetop wall 96 and prevents the RF electromagnetic field from flowing out of the aerosol-generating article through thetop wall 96.

As shown in fig. 4b, when the aerosol-generatingarticle 90 is received in thearticle cavity 14 of theheating unit 70, thebottom wall 94 of the aerosol-generatingarticle 90 contacts thebottom wall 78 of thearticle cavity 14 and theside wall 98 of the aerosol-generatingarticle 90 contacts theside wall 76 of thearticle cavity 14. Thetop wall 96, which is formed of a material that is opaque to RF electromagnetic fields, is aligned with and in contact with theside wall 76 of thearticle cavity 14, which is also formed of a material that is opaque to RF electromagnetic fields. In this position, the aerosol-formingsubstrate 92 is surrounded by a material that is opaque to RF electromagnetic fields at thetop wall 96 of the aerosol-generatingarticle 90 and at theside walls 76 and bottom 78 of thearticle cavity 14. Theslot 79 in thebase 78 of thearticle cavity 14 is the only entry and exit point for the RF electromagnetic field into and out of the aerosol-formingsubstrate 92.

When a user draws on themouthpiece 64 of thehookah device 50, air is drawn into thehookah device 50 through thetop wall 96 of theaerosol generating article 90. The air flow path through the aerosol-generatingarticle 90 and theheating unit 70 is shown by the arrows in figure 4 b. Air is drawn into the aerosol-generatingarticle 90 through thetop wall 96 of the aerosol-generatingarticle 90, through the aerosol-formingsubstrate 92, and into theresonant cavity 80 of theheating unit 70 through thebottom wall 94 of the aerosol-generatingarticle 90 and theslots 79 in thebottom wall 78 of thearticle cavity 14. Air is drawn from theresonant cavity 80 into theairflow conduit 72 through anopening 73 in theouter housing 71 of theheating unit 70.

In use, when thehookah apparatus 50 is activated by a user, power is supplied to theelectromagnetic field generator 11 from the power source. In this embodiment, the hookah apparatus is activated by a user pressing an activation button (not shown) provided on an exterior surface of theheating unit 70. It should be understood that in other embodiments, the hookah apparatus may be activated in another manner, such as upon detecting a user drawing on themouthpiece 64 via a draw sensor disposed on themouthpiece 64. When power is supplied to theelectromagnetic field generator 11, theelectromagnetic field generator 11 generates an RF electromagnetic field having a frequency between 900MHz and 2.4GHz and amplifies the RF electromagnetic field. The RF electromagnetic field is guided along thewaveguide 15 by theantenna 16 into theresonant cavity 80. The RF electromagnetic field propagates from theresonant cavity 80 into the aerosol-formingsubstrate 92 of the aerosol-generatingarticle 90 via theslot 79 in thebottom wall 78 of thearticle cavity 14 and thebottom wall 94 of the aerosol-generatingarticle 90. Thetop wall 96 of the aerosol-generatingarticle 90 prevents the RF electromagnetic field from exiting the aerosol-generatingarticle 90. The RF electromagnetic field dielectrically heats the aerosol-formingsubstrate 90, which releases volatile compounds. As described above, a feedback control mechanism may be used to regulate the temperature in theproduct chamber 14. The temperature inside thearticle cavity 14 may be sensed, or another parameter indicative of the temperature inside the substrate cavity may be sensed, to provide a feedback signal to the control circuitry of thehookah apparatus 50. The control circuitry is configured to adjust the frequency or amplitude, or both, of the RF electromagnetic field in order to maintain the temperature inside thearticle cavity 14 within a desired temperature range.

As a user draws on themouthpiece 64 of thehookah device 50, volatile compounds released from the heated aerosol-formingsubstrate 90 are entrained in the airflow through the aerosol-generatingarticle 90 and are drawn from the aerosol-generatingarticle 90, through theresonant cavity 80 and into theairflow conduit 72. As described above, volatile compounds are drawn from the airflow conduit through thehookah device 50 to and from themouthpiece 66.

Figure 5 illustrates aheating unit 70 of a hookah apparatus according to other embodiments of the present disclosure. Theheating unit 70 shown in FIG. 5 is substantially similar to theheating unit 70 shown in FIG. 4; and like reference numerals are used to denote like features.

Theheating unit 70 shown in fig. 5a differs from theheating unit 70 shown in fig. 4 in that thebase 78 of theproduct chamber 14 does not include aslot 79 and, therefore, RF electromagnetic radiation cannot propagate from theresonant cavity 80 into theproduct chamber 14 through thebase 78 of theproduct chamber 14. In the embodiment of FIG. 5a, thegroove 83 is provided in theinner wall 82 and thegroove 77 is provided in theside wall 76 of theproduct chamber 14. Thus, the RF electromagnetic field can enter thearticle cavity 14 through theside wall 76 of thearticle cavity 14 via theslot 83 in theinner wall 82. This arrangement changes the size and shape of theresonant cavity 80 as compared to theresonant cavity 80 of the embodiment of fig. 4. When using RF electromagnetic fields of different frequencies, it may be necessary to change the size and shape of theresonant cavity 80 in order to ensure that the RF electromagnetic fields resonate within theresonant cavity 80.

Theheating unit 70 shown in fig. 5b differs from theheating unit 70 shown in fig. 4 in that theinner wall 82 comprises agroove 83 in addition to thebase 78 of theproduct cavity 14 comprising agroove 79, and theside wall 76 of theproduct cavity 14 comprises agroove 77, such that the RF electromagnetic field can enter theproduct cavity 14 through both thebase 78 and theside wall 76 of theproduct cavity 14. This arrangement provides additional alternative sizes and shapes for theresonant cavity 80, which may provide a suitable resonant cavity for RF electromagnetic fields of alternative frequencies.

Figure 6 illustrates aheating unit 70 and an aerosol-generatingarticle 90 of a hookah apparatus forming a hookah system according to another embodiment of the present disclosure. Theheating unit 70 and aerosol-generatingarticle 90 shown in fig. 6 are substantially similar to theheating unit 70 and aerosol-generatingarticle 90 shown in fig. 4; and like reference numerals are used to denote like features. Figure 6a shows theheating unit 70 and aerosol-generatingarticle 90 prior to insertion of the aerosol-generatingarticle 90 into thearticle cavity 14 of theheating unit 70. Figure 6b shows an aerosol-generatingarticle 90 received in thearticle cavity 14 of theheating unit 70.

Theheating unit 70 shown in fig. 6 differs from theheating unit 70 shown in fig. 4 in that thebase 78 of theproduct chamber 14, theside walls 76 and theinner walls 82 of theproduct chamber 14 are all formed from a material that is substantially transparent to RF electromagnetic fields, such as a rigid plastic material, ceramic or clay. In this embodiment, each of thebase 78 of thearticle cavity 14, theside walls 76 and theinner walls 82 of thearticle cavity 14 are each configured to be fluid permeable such that air can be drawn through each of these walls. It should be understood that in other embodiments, thebase 78 of thearticle cavity 14 may be fluid permeable and theside walls 76 and theinner walls 82 of thearticle cavity 14 may be substantially fluid impermeable, or theside walls 76 and theinner walls 82 of thearticle cavity 14 may be fluid permeable and thebase 78 of thecavity 14 may be substantially fluid impermeable.

The aerosol-generatingarticle 90 shown in figure 6 differs from the aerosol-generatingarticle 90 shown in figure 4 in that thebottom wall 94 and theside wall 80 of the aerosol-generating article are formed from a material that is opaque to RF electromagnetic fields. To allow the RF electromagnetic field to enter the aerosol-generatingarticle 90 and heat the aerosol-formingsubstrate 92, a plurality ofslots 95 are provided in thebottom wall 94 and theside wall 90. It will be appreciated that in some embodiments, only one slot will be provided in one of the bottom and top walls. It will also be appreciated that the size and shape of the one or more slots may vary depending on the geometry of the aerosol-generating article and the hookah apparatus. In this embodiment, theslot 95 is also fluid permeable to thebottom wall 95 and theside wall 98 such that air can be drawn through the aerosol-generatingarticle 90 and into theheating unit 70 of thehookah apparatus 50.

An advantage of providing the bottom wall and the side walls of the aerosol-generating article with a material that is opaque to RF electromagnetic fields is that the number, size, shape and arrangement of the slots in the bottom wall and the side walls may be selected depending on the aerosol-forming substrate that the aerosol-generating article encapsulates. The number, size, shape and arrangement of the slots in the bottom wall and the side wall may affect the RF electromagnetic field within the aerosol-generating article, thereby affecting the heating of the aerosol-forming substrate and the temperature to which the aerosol-forming substrate is heated.

Figure 7 illustrates aheating unit 70 and an aerosol-generatingarticle 90 for a hookah apparatus according to another embodiment of the present disclosure. Theheating unit 70 and aerosol-generatingarticle 90 shown in fig. 7 are substantially similar to theheating unit 70 and aerosol-generating article shown in fig. 4; and like reference numerals are used to denote like features.

Theheating unit 70 shown in fig. 7 comprises anouter housing 71 forming a cylindrical tube open at one end and substantially closed at the opposite end. Theouter housing 71 is formed of a material that is opaque to RF electromagnetic radiation.

Thearticle cavity 14 is defined within theouter housing 71 and is sized and shaped to receive an aerosol-generatingarticle 90. The heating unit is disposed above thereceptacle 52 of thehookah apparatus 50 by anair flow conduit 72 that extends into the substantially closed end of theouter housing 71 of theheating unit 70 to fluidly connect theproduct chamber 14 to thereceptacle 52 of thehookah apparatus 50. A radiation shielding element in the form of a metal mesh (not shown) is disposed in theairflow conduit 72 to prevent the RF electromagnetic field from flowing out of thearticle cavity 14 through theairflow conduit 72.

Theheating unit 70 shown in fig. 7 differs from theheating unit 70 shown in fig. 4 in that theheating unit 70 shown in fig. 7 includes aclosure 75. Theclosure 75 is movable over the open end of theouter housing 71 of theheating unit 70 to substantially close the open end. Theenclosure 75 includes an outer housing similar to theouter housing 71 of the heating unit, formed of the same material that is opaque to RF electromagnetic fields, and sized and shaped to align and engage with theouter housing 71 to close the open end. Theclosure 75 is rotatably connected to theouter housing 71 by a hinge and is rotatable between an open position as shown in fig. 7a and a closed position as shown in fig. 7 b. When theclosure 75 is in the open position, the open end of theouter shell 71 is open for insertion of the aerosol-generatingarticle 90 into thearticle cavity 14 and for removal of the aerosol-generatingarticle 90 from thearticle cavity 14. When theclosure 75 is in the closed position, thearticle cavity 14 is surrounded by a material that is opaque to the RF electromagnetic field such that the RF electromagnetic field cannot propagate from thearticle cavity 14.

In this embodiment, theenclosure 75 further includes anelectromagnetic field generator 11 in the form of a solid state RF LDMOS transistor, awaveguide 15 coupled to the output of the RF solid state transistor, aresonant cavity 80, and anantenna 16 coupled to thewaveguide 16 and positioned in theresonant cavity 80. In this embodiment, theresonant cavity 80 comprises a substantially cylindrical body of dielectric material encased in an outer metal container. The outer metal receptacle of theresonant cavity 80 comprises a pair ofslots 79 arranged such that when theenclosure 75 is in the closed position, an RF electromagnetic field can be generated and directed by theelectromagnetic field generator 11 into theresonant cavity 80 and propagate from theresonant cavity 80 into theproduct cavity 14. A control circuit (not shown) and a battery (not shown) are also included in theenclosure 75 to provide a controlled supply of power to theelectromagnetic field generator 11.

It will be appreciated that in some embodiments, the hookah device may include electrical components on thecontainer 50 ormouthpiece 64 that require power from a battery or control from a control circuit. In these embodiments, a flexible circuit or wire may be provided from the control circuit and battery in theenclosure 75 through the hinge to components disposed elsewhere on thehookah apparatus 50.

In this embodiment, theenclosure 75 also includes an air inlet (not shown) in the form of a region of fluid permeable material that is opaque to the RF electromagnetic field. The air inlet enables air to be drawn into theproduct chamber 14 when theclosure 75 is in the closed position.

The reason for this embodiment having a particularly advantageous configuration is that it is simple to manufacture and comprises relatively few component parts. Furthermore, since thearticle cavity 14 is completely surrounded by a material that is opaque to RF electromagnetic fields, there is no need for the aerosol-generatingarticle 90 to have any exterior surface formed from a material that is opaque to RF electromagnetic fields. Since the aerosol-generatingarticle 90 is typically a disposable component of a hookah system, this may reduce the cost of manufacturing the aerosol-generatingarticle 90.

Figure 8 illustrates aheating unit 70 and an aerosol-generatingarticle 90 for ahookah apparatus 50 according to another embodiment of the present disclosure. Theheating unit 70 and aerosol-generatingarticle 90 shown in fig. 8 are substantially similar to theheating unit 70 and aerosol-generatingarticle 90 shown in fig. 7; and like reference numerals are used to denote like features. Figure 7a shows theheating unit 70 and aerosol-generatingarticle 90 prior to insertion of the aerosol-generatingarticle 90 into thearticle cavity 14 of theheating unit 70. Figure 7b shows an aerosol-generatingarticle 90 received in thearticle cavity 14 of theheating unit 70.

Theheating unit 70 shown in fig. 8 differs from theheating unit 70 shown in fig. 7 in that theheating unit 70 shown in fig. 8 includes theelectromagnetic field generator 11, thewaveguide 15, theantenna 60, and theresonant cavity 80 in anouter housing 71 instead of in theenclosure 75. In this embodiment, theenclosure 75 is simply a cover for enclosing thearticle cavity 14 to prevent the RF electromagnetic field from escaping thearticle cavity 14.

Theresonant cavity 80 of theheating unit 70 shown in fig. 8 comprises a substantially annular body of dielectric material enclosed in an outer metal container. Theresonant cavity 80 includes a tapered inner passage that widens towards the open end of theouter housing 71. In this embodiment, the inner channel of theresonant cavity 80 substantially defines thearticle cavity 14, which is configured to receive a substantially frusto-conical aerosol-generatingarticle 90. A plurality ofslots 79 are provided at the inner passage in the outer metal receptacle of theresonant cavity 80 to enable the RF electromagnetic field to propagate into thearticle cavity 14.

In this embodiment, the air flow path through theheating unit 70 passes substantially longitudinally through thearticle cavity 14 in the direction of theairflow conduit 72, and the RF electromagnetic field propagates from theresonant cavity 80 into thearticle cavity 14 in a direction substantially transverse to the airflow. This arrangement ensures that the electromagnetic field generating device is removed from the air flow path through theheating unit 70. This type of arrangement may make it easier to control the resistance to suction through theheating unit 70. This type of arrangement may also make temperature management of the electromagnetic field generating device more straightforward, as the temperature of the electromagnetic field generating device is less likely to fluctuate during use due to the user drawing on the apparatus and drawing air over the electromagnetic field generating device.

Figure 9 illustrates a hookah system according to another embodiment of the present disclosure. The hookah system is similar to that shown in figure 3 and like reference numerals are used to denote like features.

Thehookah apparatus 50 includes acontainer 52 defining aliquid chamber 54 that is divided into two sections, aliquid section 56 that includes a volume of liquid and aheadspace 58 above the liquid section. In this embodiment, thecontainer 52 is substantially cylindrical. Aliquid fill level 60 is defined at the boundary betweenliquid section 56 andheadspace 58, and is bounded on the exterior surface ofcontainer 52 by dashedline 60. Aheadspace outlet 62 is provided on the sidewall of thecontainer 52 above the liquid fill level and is configured to enable fluid to be drawn from the liquid chamber at theheadspace 58. Themouthpiece 64 is connected to theheadspace outlet 62 by aflexible hose 66.

Thecontainer 52 is arranged on aheating unit 70, which in this embodiment is a cylindrical unit having a diameter substantially equal to the diameter of thecontainer 52. Thus, when thecontainer 52 and theheating unit 70 are arranged together for use, thehookah apparatus 50 forms a substantially cylindrical unit.

Theheating unit 70 is substantially similar to the heating unit shown in fig. 7; and like reference numerals are used to describe like features.

Theheating unit 70 includes anouter housing 71 formed of a material that is opaque to RF electromagnetic radiation. Theouter housing 71 forms a cylindrical tube that is substantially closed at both ends. A door (not shown) is formed in a sidewall of theouter case 71 and is coupled to the sidewall by a hinge. The door is rotatable between an open position and a closed position to allow insertion and removal of the aerosol-generating article into and from theheating unit 70. The door may be locked in a closed position to ensure that the door does not open when thehookah apparatus 50 is operating, and is formed from a metal mesh that is opaque to RF electromagnetic radiation but fluid permeable so that ambient air may be drawn into theheating unit 70.

Anarticle cavity 14 for receiving an aerosol-generatingarticle 90 is defined in theheating unit 70. In this embodiment, thearticle cavity 14 is substantially frustoconical such that thearticle cavity 14 is configured to receive a substantially frustoconical aerosol-generatingarticle 90. Theproduct chamber 14 is disposed above theresonant chamber 80. In this embodiment, theresonant cavity 80 comprises a substantially cylindrical body of dielectric material encased in an outer metal container. The outer metal receptacle of theresonant cavity 80 includes a pair ofslots 79 arranged to enable the propagation of the RF electromagnetic field from theresonant cavity 80 into thearticle cavity 14.

Anelectromagnetic field generator 11 in the form of a solid state RF LDMOS transistor is disposed below theresonant cavity 80. The output of theelectromagnetic field generator 80 is coupled to awaveguide 15 in the form of a waveguide. Thewaveguide 15 is arranged to guide the RF electromagnetic field generated by theelectromagnetic field generator 11 to theantenna 16, which is arranged in theresonant cavity 80. By this arrangement, the RF electromagnetic field generated by theelectromagnetic field generator 11 is directed to theresonant cavity 80 and propagates out of theresonant cavity 80 through theslot 79 into thearticle cavity 14 for heating the aerosol-forming substrate arranged in thearticle cavity 14. Theelectromagnetic field generator 11 is connected to a control circuit (not shown) and a lithium ion battery (not shown) arranged and configured to control the powering of theelectromagnetic field generator 11 to control the RF electromagnetic field generated by theelectromagnetic field generator 11.

Anair flow conduit 72 extends from theproduct cavity 14 into thecontainer 52 to a location below theliquid fill level 60 in theliquid section 56. Anair flow conduit 72 fluidly connects the product chamber to theliquid section 56 of thecontainer 52. To prevent liquid from flowing from theliquid section 56 into theproduct cavity 14 through theair flow conduit 72 under the influence of gravity, a one-way valve (not shown) is arranged in theair flow conduit 72 at anopening 73 between theheating unit 70 and thecontainer 52. The one-way valve does not allow fluid to flow from thecontainer 52 into theheating unit 70 and also requires that a minimum pressure be reached before fluid can flow from theheating unit 70 to thecontainer 52.

In use, when a user draws on themouthpiece 64, ambient air is drawn into thehookah apparatus 50 through the mesh door (not shown) and into thearticle cavity 14. As air flows into thearticle cavity 14, a puff sensor (not shown) disposed in thearticle cavity 14 and connected to the control circuitry and the battery senses that the user is puffing on themouthpiece 64. When the puff sensor detects that a user puffs on themouthpiece 64, the control circuitry supplies power from the battery to theelectromagnetic field generator 11 so that the RF electromagnetic field propagates into thearticle cavity 14 and heats the aerosol-forming substrate in the aerosol-generatingarticle 90. The volatile compounds are released from the heated aerosol-forming substrate. The air drawn into thearticle cavity 14 entrains the released volatile compounds and the entrained volatile compounds are drawn through theair flow conduit 72, through the one-way valve, and into theliquid section 56 of thecontainer 52. The volatile compounds cool in the volume of liquid in theliquid section 56 and are released from the liquid into theheadspace 58 where they condense to form an aerosol. The aerosol is drawn from theheadspace 58 through theheadspace outlet 62, along thehose 66 to themouthpiece 64 for inhalation by the user.

It should be appreciated that the above-described embodiments are merely illustrative examples, and that other embodiments in accordance with the present disclosure are contemplated. For example, it will be appreciated that the heating unit embodiments described above may be used with any suitable design of hookah apparatus, such as the apparatus shown in fig. 3 and 9. For example, it should also be understood that the container, aerosol-forming article and any other features of a hookah system according to the present disclosure may be any other shape and size as desired. For example, the liquid in the liquid section of the hookah apparatus is preferably water, but may be another suitable liquid.

Claims (15)

Translated fromChinese

1.一种用于加热气溶胶形成基质以生成气溶胶的水烟装置，所述水烟装置包括：1. A hookah device for heating an aerosol-forming substrate to generate an aerosol, the hookah device comprising:液体腔，所述液体腔容纳一定体积的液体，所述水烟装置生成的气溶胶在由使用者吸入之前抽吸通过所述一定体积的液体，所述液体腔具有顶部空间出口；a liquid cavity containing a volume of liquid through which the aerosol generated by the hookah device is drawn before being inhaled by a user, the liquid cavity having a headspace outlet;制品腔，所述制品腔被构造成接收气溶胶形成基质，所述制品腔与所述液体腔流体连通；以及an article chamber configured to receive an aerosol-forming substrate, the article chamber in fluid communication with the liquid chamber; and电磁场发生器，所述电磁场发生器被构造成在所述制品腔中产生射频(RF)电磁场，所述电磁场发生器包括磁控管或固态RF晶体管。An electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in the article cavity, the electromagnetic field generator comprising a magnetron or solid state RF transistor.2.根据权利要求1所述的水烟装置，其中所述电磁场发生器包括固态RF晶体管，并且其中所述固态RF晶体管被构造成生成并放大所述RF电磁场。2. The hookah device of claim 1, wherein the electromagnetic field generator comprises a solid state RF transistor, and wherein the solid state RF transistor is configured to generate and amplify the RF electromagnetic field.3.根据权利要求1或权利要求2所述的水烟装置，其中所述制品腔包括由对所述RF电磁场不透的材料形成的一个或多个外部壁，并且其中一个或多个槽形成于所述一个或多个外部壁中。3. The hookah device of claim 1 or claim 2, wherein the article cavity comprises one or more outer walls formed of a material impermeable to the RF electromagnetic field, and wherein the one or more grooves are formed in in the one or more outer walls.4.根据权利要求1至3中任一项所述的水烟装置，其中所述制品腔包括用于接收包括所述气溶胶形成基质的气溶胶形成制品的开口端和基本封闭端。4. The hookah device of any one of claims 1 to 3, wherein the article cavity includes an open end and a substantially closed end for receiving an aerosol-forming article comprising the aerosol-forming substrate.5.根据权利要求1至4中任一项所述的水烟装置，还包括天线，所述天线连接到所述电磁场发生器，所述天线被构造成引导所述RF电磁场。5. The hookah device of any one of claims 1 to 4, further comprising an antenna connected to the electromagnetic field generator, the antenna being configured to direct the RF electromagnetic field.6.根据权利要求5所述的水烟装置，其中所述天线至少部分地位于所述制品腔中。6. The hookah device of claim 5, wherein the antenna is located at least partially within the article cavity.7.根据权利要求1至6中任一项所述的水烟装置，还包括在所述制品腔与所述电磁场发生器之间的谐振腔。7. The hookah device of any one of claims 1 to 6, further comprising a resonant cavity between the article cavity and the electromagnetic field generator.8.根据权利要求1至7中任一项所述的水烟装置，包括在所述制品腔中或邻近所述制品腔的传感器，所述传感器提供指示所述制品腔中的温度的信号；以及控制器，所述控制器被连接以从所述传感器接收信号并且被连接以根据来自所述传感器的信号控制所述电磁场发生器。8. The hookah device of any one of claims 1 to 7, comprising a sensor in or adjacent to the article cavity, the sensor providing a signal indicative of the temperature in the article cavity; and a controller connected to receive signals from the sensors and connected to control the electromagnetic field generators based on the signals from the sensors.9.一种水烟系统，包括：根据权利要求1至8中任一项所述的水烟装置；以及气溶胶生成制品，所述气溶胶生成制品包括气溶胶形成基质。9. A hookah system comprising: a hookah device according to any one of claims 1 to 8; and an aerosol-generating article comprising an aerosol-forming substrate.10.根据权利要求9所述的水烟系统，其中所述气溶胶形成基质包括烟草。10. The hookah system of claim 9, wherein the aerosol-forming substrate comprises tobacco.11.根据权利要求9或10所述的水烟系统，其中所述气溶胶生成制品包括由对所述RF电磁场不透的材料形成的一个或多个外部表面。11. The hookah system of claim 9 or 10, wherein the aerosol-generating article includes one or more exterior surfaces formed from a material that is impermeable to the RF electromagnetic field.12.根据权利要求11所述的水烟系统，其中一个或多个槽形成于由对所述RF电磁场不透的材料形成的一个或多个外部表面中。12. The hookah system of claim 11, wherein one or more grooves are formed in one or more exterior surfaces formed from a material that is impervious to the RF electromagnetic field.13.根据权利要求11或12所述的水烟系统，其中对所述RF电磁场不透的材料在所述一个或多个外部表面上形成涂层。13. The hookah system of claim 11 or 12, wherein a material impermeable to the RF electromagnetic field forms a coating on the one or more exterior surfaces.14.一种用于水烟系统的气溶胶生成制品，所述气溶胶生成制品包括：14. An aerosol-generating article for use in a hookah system, the aerosol-generating article comprising:气溶胶形成基质；以及aerosol-forming substrates; and由对RF电磁场不透的材料形成的一个或多个外部表面，其中对所述RF电磁场不透的材料是流体可渗透的。One or more exterior surfaces formed from a material that is impervious to RF electromagnetic fields, wherein the material that is impervious to RF electromagnetic fields is fluid permeable.15.根据权利要求14所述的气溶胶生成制品，其中对所述RF电磁场不透的材料是金属网。15. The aerosol-generating article of claim 14, wherein the material impermeable to the RF electromagnetic field is a metal mesh.

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